As a conventional device with a heat pump, Patent Document 1 discloses a water heater. The water heater of Patent Document 1 includes a heat exchanger that functions as an evaporator evaporating a refrigerant, and a blower fan that sends outside air to the heat exchanger. The heat exchanger is inclined with respect to a flow of the outside air toward a downstream side. According to this, since condensed water on the heat exchanger is moved on the heat exchanger by wind power of the outside air sent by the blower fan, drainage of the condensed water can be improved.
In recent years, as a kind of a conex box transported by a trailer or the like, there is a container for housing fresh food and frozen food in a cooled condition. The container includes an internal temperature adjusting device that maintains inside temperature at a target temperature. The internal temperature adjusting device includes a heat pump, for example. The internal temperature adjusting device with the heat pump includes an internal heat exchanger that exchanges heat between a heat medium and air inside the container, and an external heat exchanger that exchanges heat between the heat medium and air outside the container. In a cooling operation, the internal temperature adjusting device decreases temperature inside the container by using the internal heat exchanger as an evaporator, and by using the external heat exchanger as a condenser. In a heating operation, the internal temperature adjusting device increases temperature inside the container by using the internal heat exchanger as a condenser, and by using the external heat exchanger as an evaporator.
In the internal temperature adjusting device, condensed water is generated on the external heat exchanger when the heating operation is performed. When the trailer transporting the container runs in a cold area, for example, the condensed water generated on the external heat exchanger may become frost. Since the frost decreases a heat exchange capacity of the external heat exchanger, the internal temperature adjusting device periodically performs a defrosting operation by temporarily performing the cooling operation. According to this, the external heat exchanger is heated, and the frost on the external heat exchanger is melted and removed. When the condensed water remains on the external heat exchanger after the defrosting operation, frost is generated again after restarting the heating operation. Accordingly, the external heat exchanger needs to have a high drainage.
It may be considered to adopt the structure of the heat exchanger of Patent Document 1 as the structure of the external heat exchanger. That is, it may be considered to improve drainage of the external heat exchanger by providing the external heat exchanger so as to incline with respect to a vertical direction. However, since a space in the container for the external temperature adjusting device is limited, it may be difficult to secure a space for inclining the external heat exchanger.